In accordance with a rapid spread of information relevant apparatuses and communication apparatuses such as a personal computer, a video camera and a portable telephone in recent years, the development of a battery excellent as a power source thereof has been emphasized. Also, in the field except information relevant apparatuses and communication relevant apparatuses, the development of a lithium ion battery has been advanced as a battery to be used for an electric automobile and a hybrid automobile in the automobile industry, for example.
Liquid electrolyte containing a flammable organic solvent is used for a presently commercialized lithium battery, so that the installation of a safety device for restraining temperature rise during a short circuit and the structure for preventing the short circuit are necessary therefor. In contrast, a lithium battery all-solidified by replacing the liquid electrolyte with a solid electrolyte layer is conceived to intend the simplification of the safety device and be excellent in production cost and productivity for the reason that the flammable organic solvent is not used in the battery. In addition, among all solid state batteries, an all solid state battery using a sulfide solid electrolyte material has the advantage that Li ion conductivity is excellent.
For example, in Patent Literature 1, a solid state battery using a sulfide solid electrolyte material of glass ceramics obtained by mixing and heating sulfides such as Li2S and P2S5 and LiI is disclosed.
Also, in Patent Literature 2, a technique for improving cycling characteristics of a battery by forming a two-layer solid electrolyte layer with different materials is disclosed as a technique for improving battery performance of a solid state battery. In addition, in Patent Literature 3, a technique for improving interlaminar adhesion properties of a battery by laminating a cathode layer, a crystalline crystal electrolyte layer, a glassy glass electrolyte layer and an anode layer in this order is disclosed.